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Along come a pair of LX13s...
Hi Folks. It's been a few years since I acquired the parts for my next speaker, but still have not started the cabinets.
Anyway, along come a pair of LX13s. The cost of the parts to build the xo in this thread isn't much cheaper, and these come in a nice jbl box, so I thought why not? I'll just add the CD compensation to it.
So off I go to take some measurements. I thought I would share these with you guys, and I have a few questions at the end.
The first chart shows the response of the 2445j on a 2380a horn with three different cap values in parallel with the hi-pass section of the xo. What I found interesting is how they all behaved. Note 3rd octave smoothing applied to make it easier to see.
The blue line is a 3.0uf cap, which provides the most boost centred around 20khz.
The red line is a 6.2uf cap, which provides the most boost centred around 15khz.
The green line is a 9.1uf cap, which provides the most boost centred around 10khz.
To my aging ears, the 9.1uf cap provided the most pleasing overall sound, even though it rolls off at the top end quicker than the other caps.
Chart A
The next chart shows the difference between having the 9.1uf cap in and out of the circuit. Again, 3rd octave smoothing applied.
Chart B
Finally, here is the second chart again, but without smoothing (just gating). Except for the dips around 8khz, I think it looks pretty good.
Chart C
Now I have a few questions:
1 - Is there any way to keep the response from falling when using the 9.1uf cap? Ideally I would like the boost at 10khz offered by the 9.1uf cap and the boost at 20khz of the 3.0uf cap combined.
2 - Looks like the biggest boost in chart B is about 7db at 11khz, but the HF gain is in the min position which should be a 10db reduction. Any ideas why I'm not getting a 10db boost?
Thanks.